Spectral IP studies of Finnish ore prospects

Abstract

Spectral-induced polarization (IP) field measurements, both in the frequency domain and in the time domain, were made at six early Proterozoic sulfide, oxide, and graphitic-gneiss deposits in Finland. Core samples were also measured. Deposits with large differences in texture can be separated on the basis of their phase-spectra time constants. A good correlation was found between the observed grain size in thin sections and the grain size calculated from the apparent, field-survey phase spectra in the case of homogeneous, disseminated textures. The measured frequency-domain phase spectra, and phase spectra calculated from the time-domain Cole-Cole parameters are very similar in a comparable frequency band. -from Authors